Emulsification is a powerful age-old technique for mixing and dispersing immiscible inner phases within a continuous liquid phase. Consequently, emulsions are central components of medicine, food, and performance materials. Complex emulsions, including multiple emulsions and Janus droplets, are of increasing importance in pharmaceuticals and medical diagnostics, in the fabrication of microdroplets and capsules for food, in chemical separations, for cosmetics, and for performance materials like paints and coatings. As complex emulsion properties and functions are generally related to droplet geometry and composition, the development of rapid and facile fabrication approaches allowing precise control over the droplets' physical and chemical characteristics is critical. Significant advances in the fabrication of complex emulsions have been accomplished by a number of procedures, ranging from large-scale less precise techniques that give compositional heterogeneity using high-shear mixers and membranes to small-volume microfluidic methods. However, such approaches have yet to create droplet morphologies that can be controllably altered after emulsification.